     (.set a val))
   (setBoxed [a i j val]
     (.set a i j val))
-  (alter [a i j f]
+  (alter [a _]
+    (throw (UnsupportedOperationException. INEFFICIENT_OPERATION_MSG)))
+  (alter [a _ _ _]
     (throw (UnsupportedOperationException. INEFFICIENT_OPERATION_MSG)))
   RealMatrix
   (mrows [_]

    (.set a val))
  (setBoxed [a i j val]
    (.set a i j val))
  (alter [a i j f]
    (throw (UnsupportedOperationException. INEFFICIENT_OPERATION_MSG)))
  RealMatrix
  (mrows [_]

    (.set x val))
  (setBoxed [x i val]
    (.set x i val))
  (alter [_ _]
    (throw (UnsupportedOperationException. INEFFICIENT_OPERATION_MSG)))
  (alter [_ _ _]
    (throw (UnsupportedOperationException. INEFFICIENT_OPERATION_MSG)))
  RealVector
